AB1072 ANKYLOSING SPONDYLITIS: UNEARTHING THE ASSOCIATION BETWEEN ACTIVE SACROILIITIS ON MRI AND C-REACTIVE PROTEIN AS A MARKER OF INFLAMMATION
Authors: H. EL-Kasmi, N. Akasbi, I. El Mezouar, M. Omari, T. Harzy
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Ankylosing spondylitis (AS) is a chronic autoimmune disorder that causes inflammation in the joints, particularly the sacroiliac joints. Magnetic resonance imaging (MRI) is a non-invasive and objective tool that can be used for early diagnosis of AS. C-reactive protein (CRP) is a biomarker that is commonly used to evaluate disease activity in AS patients, and is included in the Ankylosing Spondylitis Disease Activity Score with C-reactive protein (ASDAS-CRP). <h3>Objectives</h3> The primary outcome of the study to investigate the association between active sacroiliitis on MRI and CRP levels in AS patients. The secondary outcome was to identify other parameters that may be associated with sacroiliitis activity in AS patients. The study was a retrospective analysis that included 140 AS patients who had MRI of their sacroiliac joints between January 2011 and March 2022. <h3>Methods</h3> Retrospective study was conducted on all SpA cases that were established between January 2011 and March 2022. The study aimed to explore the relationship between sacroiliitis as detected on MRI and C - reactive protein (CRP) levels in patients with Ankylosing Spondylitis. Magnetic Resonance Imaging (MRI) of the sacroiliac joints was performed on all patients using coronal oblique T1, T2 and STIR weighted sequences. Active sacroiliitis was defined as the presence of inflammatory lesions according to the ASAS (Assessment of SpondyloArthritis international Society) criteria. CRP was considered high if it was greater than or equal to 6 mg/L. The statistical analysis was performed using the Fisher and Chi-Squared test and a p-value of 0.05 was considered as the level of significance. <h3>Results</h3> MRI of the sacroiliac joints was performed in 140 patients; the mean age was 47.54± 14.46 years with a predominantly female sex ratio of 0.34 (M/F). The mean duration of evolution was 5.40± 5.13. Active sacroiliitis was found in 65% of the patients, it was bilateral in 31.4%, unilateral in 28.6% (15% left and 13.6% right). An elevated CRP was found in 60.3% of the patients, the mean CRP was 21.79± 44.68, and the mean sedimentation rate was 26.04± 26.12. Active sacroiliitis did not have a statically significant association with an elevated CRP level. For the other clinico-biological parameters, Young onset was significantly associated with active sacroiliitis (p&lt;0.05). <h3>Conclusion</h3> In conclusion, this study did not demonstrate a significant association between CRP levels and active sacroiliitis on MRI in patients with AS. However, the study suggests that MRI may allow for an early diagnosis of AS in the absence of biological inflammation, and that young onset may be a risk factor for active sacroiliitis in AS patients. Further studies are needed to validate these findings and to better understand the relationship between CRP levels, imaging, and sacroiliitis activity in AS patients. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.